Description

MR Series: -Primary current: Secondary current: Standard approval: Maximum voltage: Frequency: Rated load: Class: Short-time thermal current: Rated security coefficient: *0A****0A 5A, 1A BS***6, IEC**5 0.*2KV ****0Hz 5VA**5VA 1.0, 3.0 Ith=*0 X Ih FS<5 PRSeries: Protective current transformers are required to operate over a range of current many times the circuit rating and is frequently subjected to conditions greatly exceeding those which it would be subjected to as a measuring current transformer. When a current transformer is used to energise a protective relay, it must maintain its characteristic ratio up to some multiple offered rated current. This multiple, may be 5, *0, *0 or some even higher value and is know as the Accuracy Limit Factor(ALF). Therefore, the selection of Protective Current Transformers in relation to accuracy class and ALF require a close examination of relay characteristic and circuit conditions which includes the relay burden and the pilot wire lead burden